US20060138281A1 - Flight lock actuator with dual energy sources - Google Patents
Flight lock actuator with dual energy sources Download PDFInfo
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- US20060138281A1 US20060138281A1 US11/335,949 US33594906A US2006138281A1 US 20060138281 A1 US20060138281 A1 US 20060138281A1 US 33594906 A US33594906 A US 33594906A US 2006138281 A1 US2006138281 A1 US 2006138281A1
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- United States
- Prior art keywords
- motor
- actuator
- energy storage
- aircraft
- lock actuator
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C1/00—Fuselages; Constructional features common to fuselages, wings, stabilising surfaces or the like
- B64C1/14—Windows; Doors; Hatch covers or access panels; Surrounding frame structures; Canopies; Windscreens accessories therefor, e.g. pressure sensors, water deflectors, hinges, seals, handles, latches, windscreen wipers
- B64C1/1407—Doors; surrounding frames
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- E—FIXED CONSTRUCTIONS
- E05—LOCKS; KEYS; WINDOW OR DOOR FITTINGS; SAFES
- E05B—LOCKS; ACCESSORIES THEREFOR; HANDCUFFS
- E05B81/00—Power-actuated vehicle locks
- E05B81/24—Power-actuated vehicle locks characterised by constructional features of the actuator or the power transmission
- E05B81/25—Actuators mounted separately from the lock and controlling the lock functions through mechanical connections
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K7/00—Arrangements for handling mechanical energy structurally associated with dynamo-electric machines, e.g. structural association with mechanical driving motors or auxiliary dynamo-electric machines
- H02K7/06—Means for converting reciprocating motion into rotary motion or vice versa
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- E—FIXED CONSTRUCTIONS
- E05—LOCKS; KEYS; WINDOW OR DOOR FITTINGS; SAFES
- E05B—LOCKS; ACCESSORIES THEREFOR; HANDCUFFS
- E05B47/00—Operating or controlling locks or other fastening devices by electric or magnetic means
- E05B47/0001—Operating or controlling locks or other fastening devices by electric or magnetic means with electric actuators; Constructional features thereof
- E05B2047/0014—Constructional features of actuators or power transmissions therefor
- E05B2047/0018—Details of actuator transmissions
- E05B2047/0023—Nuts or nut-like elements moving along a driven threaded axle
Definitions
- This invention relates to actuators used in aircraft door lock mechanisms. More specifically, this invention relates to systems and methods for improving the reliability of aircraft door flight lock actuators.
- Flight lock actuators are used in aircraft door lock mechanisms to secure a lock mechanism in the locked position during flight, or whenever aircraft power is supplied to the actuator.
- flight for safety reasons, it is conventional practice to maintain the flight lock actuator in a powered stall against its locked position stop.
- the flight lock actuator is conventionally returned to its unlocked position by a spring system. For safety reasons, limit switches and brakes are not permitted in flight lock actuators.
- Actuators built according to the present art suffer occasional failure due to damage from abruptly impacting mechanical stops at the end of an actuator's stroke, especially while being back-driven by a spring system during the unpowered extension stroke to the unlocked position. These repeated mechanical shocks to the internal mechanism of a flight lock actuator can cause jamming and mechanical failure of the actuator. In addition, actuator failure may also result from damage to a brush-type actuator motor due to prolonged periods of powered stall in the locked position.
- the aircraft flight lock actuator is a key safety element in an aircraft. Any failure in the door lock mechanism, including the flight lock actuator, should be avoided.
- an aircraft flight lock actuator having a redundant energy storage system, a motor control system and a brushless motor drive.
- the redundant energy storage system utilizes a mechanical energy storage system and an electrical energy storage system to store sufficient energy for extending the actuator to its-unlocked position after the removal of aircraft power.
- the electrical energy storage system stores electrical energy during the actuator's powered retraction to the locked position and during the period of powered stall in the locked position.
- the mechanical energy storage system also stores energy during the powered retraction stroke.
- the dual energy storage systems are fully redundant, which provides that energy stored in either system alone would be sufficient to drive the actuator to its unlocked position if the other energy storage system fails.
- a motor control system is provided that senses the rotational speed of the flight lock actuator motor, and which limits both the retract and extend strokes to a desired maximum velocity to reduce mechanical shock.
- the motor control system also limits, to a desired maximum, the current supplied to the actuator motor during a period of powered stall to prevent motor damage from overheating.
- the motor control system also includes a damper feature that is capable of effectively braking the actuator during a back-driven extension stroke to ensure a controlled arrival into the extended position mechanical stop.
- FIG. 1 is a simplified elevational view, partly in section, of an illustrative aircraft flight lock actuator mechanical system in accordance with the present invention.
- FIG. 1A is an enlargement of a portion of FIG. 1 .
- FIG. 2 is a simplified schematic block diagram of an illustrative aircraft flight lock actuator electrical system in accordance with the present invention.
- an illustrative embodiment of the flight lock actuator mechanical system includes rear housing 1 , center housing 2 , guide tube 3 , guide bushing 4 , and front cover 5 .
- a brushless DC electric motor 20 Disposed within rear housing 1 and center housing 2 is a brushless DC electric motor 20 , which includes stator 25 and rotor 26 .
- Rotor 26 includes rotor shaft 28 , which rotates with rotor 26 .
- Ball screw shaft 7 is press fit into rotor shaft 28 , so that ball screw shaft 7 also rotates with rotor 26 .
- the right-hand portion of ball screw shaft 7 is threaded to provide the central element of a ball screw assembly.
- Ball screw shaft 7 is axially and rotationally fixed to sleeve 14 .
- Pin 15 is captured within the inner race of bearing 19 , and extends diametrically through shaft 7 and sleeve 14 to ensure the fixed relationship between elements 7 and 14 .
- the rotational assembly including rotor 26 , shaft 7 , and sleeve 14 is rotatably supported by bearings 19 .
- Sleeves 11 and 14 are slidable inside the inner races of bearings 19 parallel to the longitudinal axis of shaft 7 .
- the amount by which sleeves 11 and 14 can slide in this manner is limited by the compressibility of two sets, 12 and 13 , of Belleville washers. Each set of Belleville washers is disposed between a set of two flat washers.
- the first set of Belleville washers 13 is captured between a radially outwardly extending flange on sleeve 11 and the inner race of the adjacent bearing 19
- the second set 12 is captured between a radially outwardly extending flange on sleeve 14 and the inner race of the adjacent bearing 19 .
- Belleville washer sets 12 and 13 nominally axially center sleeves 11 and 14 between bearings 19 .
- the sets of Belleville washers allow shaft 7 to temporarily shift to the left or right when the axially translating sleeve of ball screw 7 hits its outbound or inbound stop, respectively.
- the Belleville washers thereby act as resilient shock absorbers for the rotational assembly.
- the output assembly includes ball nut 27 , ball nut coupling 9 , and output ram 6 .
- Output ram 6 is attached to ball nut coupling 9 , which is in turn attached to ball nut 27 .
- the entire output assembly is able to translate axially inside guide tube 3 .
- motor 20 drives ball screw 7 to rotate
- ball nut 27 is prevented from rotating by a key on collar 8 (attached to ball nut elements 9 / 27 ), which key is slidably engaged in an axial slot in guide tube 3 .
- ball screw 7 rotates, ball nut 27 is driven (via balls (not shown) between elements 7 and 27 ) to translate axially inside guide tube 3 , causing the output assembly (especially output ram 6 ) to drive an external load through bearing 16 .
- linear translation of the output assembly including ball nut 27 causes ball screw 7 and motor 20 to rotate.
- Helical compression spring 24 may be provided as means for mechanical energy storage. Disposed within guide tube 3 , compression spring 24 is trapped between washer 10 , set against center housing 2 , and collar 8 that moves axially with ball nut 27 . In FIGS. 1 and 1 A, ball nut 27 is shown in its fully retracted position. This is the condition of the actuator mechanical system in which spring 24 is in its most compressed state. Spring 24 urges output ram 6 to extend from the fully retracted position illustrated in FIGS. 1 and 1 A to a fully extended position in which collar 8 contacts stationary bushing 30 in the right-hand end (as viewed in FIGS. 1 and 1 A) of guide tube 3 . Spring 24 applies a spring force to output ram 6 in the direction of extension regardless of the output ram's position in guide tube 3 . This includes a residual spring force applied by spring 24 in the extension direction when output ram 6 is in its fully extended position.
- motor 20 When motor 20 is driven in the appropriate direction by electrical power from the aircraft that includes the flight lock actuator, motor 20 is able to overcome the force of spring 24 and retract ball nut 27 all the way to contact another stationary stop at the left-hand end (as viewed in FIGS. 1 and 1 A) of guide tube 3 . Moreover, as long as power is thus applied to motor 20 , it is able to hold ball nut 27 in the fully retracted position with spring 24 substantially compressed.
- spring 24 When power from the aircraft is removed from the flight lock actuator, spring 24 is able to drive, even without reverse driving of motor 20 as described below, assembly 6 / 9 / 27 back to its other stop at the other (right-hand) end of guide tube 3 , thereby fully extending output ram 6 .
- Alternate means may also be used for mechanical energy storage within the scope of the present invention.
- Output ram 6 / 9 / 27 is sealed with respect to guide tube 3 using seal 18 disposed in guide bushing 30 .
- Wiper seal 17 may also be disposed in front cover 5 .
- Guide bushing 4 / 30 remains stationary and functions as the internal extension stroke mechanical stop.
- Washer 10 functions as the internal retraction stroke mechanical stop.
- motor 20 is able to continue to rotate briefly as Belleville washers 12 compress. Thereby reducing the impact of ball nut 27 on washer 10 , and allowing motor 20 to stop somewhat gradually, rather than instantaneously.
- Belleville washers 12 therefore cushion the end of the retraction stroke, thereby greatly reducing the risk of damage to any part of the apparatus at the end of retraction strokes.
- Belleville washers 13 function similarly to cushion the end of extension strokes.
- FIG. 2 A block schematic diagram of an illustrative embodiment of the flight lock actuator electrical system is shown in FIG. 2 .
- Aircraft DC power e.g., 28 volts DC
- Switch 110 is typically closed automatically when an aircraft enters a predetermined condition (e.g., a forward ground speed of a certain number of miles per hour, etc.). Switch 110 automatically re-opens when the aircraft is no longer in a condition that causes the switch to close.
- Electro-magnetic interference filter 111 is connected to terminal 112 to protect the flight lock actuator's electrical system from conducted and radiated interference from the aircraft's electrical system, and vice versa.
- Other terminals 114 and 116 may also exist in the system.
- aircraft power is conducted to motor controller 130 through diode D 1 .
- the presence or absence of aircraft power at terminal 112 is sensed by motor controller 130 via the RET/EXT (RETRACT/EXTEND) input to the motor controller. If the signal on lead RET/EXT is “high” (e.g., 18 to 29 VDC), motor controller 130 drives motor 20 to retract the actuator to its retracted position (in which the actuator locks a door-opening mechanism of the aircraft). Motor 20 will stall the actuator in the retracted position as long as aircraft power continues to be supplied.
- RET/EXT RETRACT/EXTEND
- capacitor C may be provided in electrical energy accumulator 140 .
- capacitor C charges through resistor Rc and diode D 2 .
- Zener diode Z sets the capacitor charge voltage upper limit at a value appropriate to proper circuit operation.
- all further charging current limited by charging resistor Rc, bypasses capacitor C and flows to RETURN through Zener diode Z.
- Other suitable means for electrical energy storage may also be used within the scope of the present invention.
- a rechargeable battery may be alternately provided in electrical energy accumulator 140 and charged using aircraft power from terminal 112 .
- Sensing line RET/EXT signals the removal of aircraft power by going “low” (e.g., ⁇ 0V), which signals motor controller 130 to cause any subsequently applied electrical power to rotate motor 20 in the direction required to extend the actuator to its unlocked position.
- power for motor 20 and for motor controller 130 during the extension stroke is provided by capacitor C through diode D 3 .
- the capacitor voltage will decay as current is drawn from electrical energy accumulator 140 .
- the flight lock actuator electrical components are preferably sized so that the capacitor does not discharge below a motor controller 130 operational voltage value before the extension stroke of the actuator has been completed.
- Voltage regulator 150 supplies a constant control voltage for powering the control circuitry of motor controller 130 (as distinct from powering motor 20 ).
- motor controller 130 preferably limits stroke velocity by limiting current through motor 20 .
- current controller limiting may be achieved by pulse-width-modulation of the motor power signal, or by reducing the voltage available to motor 20 .
- Current through motor 20 is measured by a voltage drop across resistor R 1 .
- the rotational speed of motor 20 is preferably limited, while still meeting a maximum allowable stroke time with appropriate margin.
- Motor 20 is typically equipped with Hall effect sensors 31 that signal the rotor's angular position to motor controller 130 . Rotational speed of motor 20 may be ascertained using the frequency of the Hall effect sensors' signal. Alternately, because a permanent magnet motor generates a back-EMF proportional to its rotational speed, the generated back-EMF may be used by motor controller 130 to ascertain the rotational speed of motor 20 .
- motor controller 130 may reduce the voltage available to motor 20 , or may pulse-width-modulate the motor power signal, so as to drop the motor rotational speed to the desired range. If current limit circuitry 160 senses that the current passing through motor 20 is higher than a predetermined value that indicates motor 20 is in a state of powered stall, current limit circuitry 160 may signal motor controller 130 to reduce the voltage available to motor 20 , or appropriately pulse-width-modulate the motor power signal, so that the current supplied during a period of powered stall does not overheat motor 20 .
- the flight lock actuator's extension stroke is typically subject to a substantial aiding force from spring 24 internal to the actuator and possibly also from springs external to the actuator in the aircraft door lock mechanism.
- the flight lock actuator electrical system in addition to limiting motor rotational speed by limiting the current to motor 20 , may seek to effectively brake motor 20 using damper circuit 170 .
- the flight actuator electrical system may shunt back-EMF (electro-motive force) generated by the motor into damper circuit 170 to place an electrical load on motor 20 .
- Logic circuitry 180 having inputs from current limit circuit 160 and motor controller 130 , monitors the predetermined condition for shunting current generated by motor 20 to damper circuit 170 .
- a permanent magnet motor generates a back-EMF proportional to its rotational speed.
- This generated back-EMF may also be used by motor controller 130 to ascertain the motor rotational speed.
- Logic circuitry 180 may monitor motor current information from current limit circuit 160 and motor rotational speed information from motor controller 130 .
- a motor current that is substantially zero, in combination with motor rotational speed in excess of a desired maximum speed are signals indicating that the aiding force has driven motor 20 to an excessive speed despite motor controller 130 reducing the motor voltage or pulse width to near zero.
- logic circuitry 180 When logic circuitry 180 senses this condition, it reacts by throwing the motor controller 130 bridge into a full wave rectifier mode (i.e., all MOSFETs “off”) to shunt all current generated by motor 20 through the MOSFETs' internal bypass diodes to a load resistor in damper circuit 170 .
- a full wave rectifier mode i.e., all MOSFETs “off”
- motor 20 By operating motor 20 as a generator in conjunction with the load resistor in damper circuit 170 , the motor speed is reduced to a desired speed that ensures a controlled arrival into the mechanical stop.
- the aircraft door flight lock actuator of the present invention utilizes a redundant energy storage system having mechanical and electrical energy storage means to store energy during the actuator's powered retraction stroke to the locked position, and subsequent period of powered stall in the locked position. Once aircraft power is removed from the flight lock actuator, the stored energy is used to power an extension stroke to the unlocked position.
- a brushless motor is used to power the actuator, and the actuator electrical system ensures that the motor does not overheat by limiting the current supplied to the motor to a desired maximum.
- the actuator electrical system ensures the controlled arrival of the actuator into its mechanical stops by limiting motor rotational speed using a current limiting method and a damper feature that effectively brakes the actuator motor. Utilizing these systems and methods, a flight lock actuator with substantially improved reliability is provided.
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Aviation & Aerospace Engineering (AREA)
- Power Engineering (AREA)
- Transmission Devices (AREA)
- Lock And Its Accessories (AREA)
- Connection Of Motors, Electrical Generators, Mechanical Devices, And The Like (AREA)
- Control Of Motors That Do Not Use Commutators (AREA)
Abstract
Description
- This application is a divisional of U.S. patent application Ser. No. 10/260,470, filed Sep. 26, 2002, which claims priority from U.S. provisional application No. 60/348,881, filed Nov. 13, 2001, both of which are hereby incorporated by reference herein in their entireties.
- This invention relates to actuators used in aircraft door lock mechanisms. More specifically, this invention relates to systems and methods for improving the reliability of aircraft door flight lock actuators. Flight lock actuators are used in aircraft door lock mechanisms to secure a lock mechanism in the locked position during flight, or whenever aircraft power is supplied to the actuator. During flight, for safety reasons, it is conventional practice to maintain the flight lock actuator in a powered stall against its locked position stop. When aircraft power is removed at the end of the flight, the flight lock actuator is conventionally returned to its unlocked position by a spring system. For safety reasons, limit switches and brakes are not permitted in flight lock actuators.
- Actuators built according to the present art suffer occasional failure due to damage from abruptly impacting mechanical stops at the end of an actuator's stroke, especially while being back-driven by a spring system during the unpowered extension stroke to the unlocked position. These repeated mechanical shocks to the internal mechanism of a flight lock actuator can cause jamming and mechanical failure of the actuator. In addition, actuator failure may also result from damage to a brush-type actuator motor due to prolonged periods of powered stall in the locked position. The aircraft flight lock actuator is a key safety element in an aircraft. Any failure in the door lock mechanism, including the flight lock actuator, should be avoided.
- Therefore, it would be desirable to provide a redundant stored energy system to power the flight lock actuator's extension stroke to the unlocked position stop. It would be further desirable to extend and retract the flight lock actuator to its mechanical stops in a controlled manner, so as to eliminate failure due to damage from abrupt impacts. It would be further desirable to power the flight lock actuator using a motor less prone to suffer damage from prolonged periods of powered stall.
- In view of the foregoing, it is an object of this invention to provide a flight lock actuator using systems and methods that significantly improve its reliability.
- These and other objects are accomplished in accordance with the principles of the present invention by providing an aircraft flight lock actuator having a redundant energy storage system, a motor control system and a brushless motor drive.
- The redundant energy storage system utilizes a mechanical energy storage system and an electrical energy storage system to store sufficient energy for extending the actuator to its-unlocked position after the removal of aircraft power. The electrical energy storage system stores electrical energy during the actuator's powered retraction to the locked position and during the period of powered stall in the locked position. The mechanical energy storage system also stores energy during the powered retraction stroke. The dual energy storage systems are fully redundant, which provides that energy stored in either system alone would be sufficient to drive the actuator to its unlocked position if the other energy storage system fails.
- A motor control system is provided that senses the rotational speed of the flight lock actuator motor, and which limits both the retract and extend strokes to a desired maximum velocity to reduce mechanical shock. The motor control system also limits, to a desired maximum, the current supplied to the actuator motor during a period of powered stall to prevent motor damage from overheating. The motor control system also includes a damper feature that is capable of effectively braking the actuator during a back-driven extension stroke to ensure a controlled arrival into the extended position mechanical stop.
- Further features of the present invention, its nature, and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments.
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FIG. 1 is a simplified elevational view, partly in section, of an illustrative aircraft flight lock actuator mechanical system in accordance with the present invention. -
FIG. 1A is an enlargement of a portion ofFIG. 1 . -
FIG. 2 is a simplified schematic block diagram of an illustrative aircraft flight lock actuator electrical system in accordance with the present invention. - As shown in
FIGS. 1 and 1 A, an illustrative embodiment of the flight lock actuator mechanical system includes rear housing 1,center housing 2,guide tube 3,guide bushing 4, andfront cover 5. Disposed within rear housing 1 andcenter housing 2 is a brushless DCelectric motor 20, which includesstator 25 androtor 26.Rotor 26 includesrotor shaft 28, which rotates withrotor 26.Ball screw shaft 7 is press fit intorotor shaft 28, so thatball screw shaft 7 also rotates withrotor 26. The right-hand portion ofball screw shaft 7 is threaded to provide the central element of a ball screw assembly.Ball screw shaft 7 is axially and rotationally fixed tosleeve 14.Pin 15 is captured within the inner race ofbearing 19, and extends diametrically throughshaft 7 andsleeve 14 to ensure the fixed relationship betweenelements - The rotational
assembly including rotor 26,shaft 7, andsleeve 14 is rotatably supported bybearings 19.Sleeves bearings 19 parallel to the longitudinal axis ofshaft 7. The amount by whichsleeves washers 13 is captured between a radially outwardly extending flange onsleeve 11 and the inner race of theadjacent bearing 19, and thesecond set 12 is captured between a radially outwardly extending flange onsleeve 14 and the inner race of theadjacent bearing 19. - Belleville
washer sets bearings 19. However, by resiliently deforming, the sets of Belleville washers allowshaft 7 to temporarily shift to the left or right when the axially translating sleeve ofball screw 7 hits its outbound or inbound stop, respectively. The Belleville washers thereby act as resilient shock absorbers for the rotational assembly. - The output assembly includes
ball nut 27,ball nut coupling 9, andoutput ram 6.Output ram 6 is attached toball nut coupling 9, which is in turn attached toball nut 27. The entire output assembly is able to translate axially insideguide tube 3. Asmotor 20drives ball screw 7 to rotate,ball nut 27 is prevented from rotating by a key on collar 8 (attached toball nut elements 9/27), which key is slidably engaged in an axial slot inguide tube 3. Asball screw 7 rotates,ball nut 27 is driven (via balls (not shown) betweenelements 7 and 27) to translate axially insideguide tube 3, causing the output assembly (especially output ram 6) to drive an external load throughbearing 16. Conversely, linear translation of the output assembly includingball nut 27 causesball screw 7 andmotor 20 to rotate. -
Helical compression spring 24 may be provided as means for mechanical energy storage. Disposed withinguide tube 3,compression spring 24 is trapped betweenwasher 10, set againstcenter housing 2, andcollar 8 that moves axially withball nut 27. InFIGS. 1 and 1 A,ball nut 27 is shown in its fully retracted position. This is the condition of the actuator mechanical system in whichspring 24 is in its most compressed state.Spring 24 urgesoutput ram 6 to extend from the fully retracted position illustrated inFIGS. 1 and 1 A to a fully extended position in which collar 8 contactsstationary bushing 30 in the right-hand end (as viewed inFIGS. 1 and 1 A) ofguide tube 3.Spring 24 applies a spring force to outputram 6 in the direction of extension regardless of the output ram's position inguide tube 3. This includes a residual spring force applied byspring 24 in the extension direction whenoutput ram 6 is in its fully extended position. - When
motor 20 is driven in the appropriate direction by electrical power from the aircraft that includes the flight lock actuator,motor 20 is able to overcome the force ofspring 24 and retractball nut 27 all the way to contact another stationary stop at the left-hand end (as viewed inFIGS. 1 and 1 A) ofguide tube 3. Moreover, as long as power is thus applied tomotor 20, it is able to holdball nut 27 in the fully retracted position withspring 24 substantially compressed. When power from the aircraft is removed from the flight lock actuator,spring 24 is able to drive, even without reverse driving ofmotor 20 as described below,assembly 6/9/27 back to its other stop at the other (right-hand) end ofguide tube 3, thereby fully extendingoutput ram 6. Alternate means may also be used for mechanical energy storage within the scope of the present invention. -
Output ram 6/9/27 is sealed with respect to guidetube 3 usingseal 18 disposed inguide bushing 30.Wiper seal 17 may also be disposed infront cover 5.Guide bushing 4/30 remains stationary and functions as the internal extension stroke mechanical stop.Washer 10 functions as the internal retraction stroke mechanical stop. Whenball nut 27hits washer 10 at the end of the retraction stroke,motor 20 is able to continue to rotate briefly asBelleville washers 12 compress. Thereby reducing the impact ofball nut 27 onwasher 10, and allowingmotor 20 to stop somewhat gradually, rather than instantaneously.Belleville washers 12 therefore cushion the end of the retraction stroke, thereby greatly reducing the risk of damage to any part of the apparatus at the end of retraction strokes.Belleville washers 13 function similarly to cushion the end of extension strokes. - A block schematic diagram of an illustrative embodiment of the flight lock actuator electrical system is shown in
FIG. 2 . Aircraft DC power (e.g., 28 volts DC) is received viaterminal 112 whenswitch 110 is closed.Switch 110 is typically closed automatically when an aircraft enters a predetermined condition (e.g., a forward ground speed of a certain number of miles per hour, etc.). Switch 110 automatically re-opens when the aircraft is no longer in a condition that causes the switch to close. Electro-magnetic interference filter 111 is connected to terminal 112 to protect the flight lock actuator's electrical system from conducted and radiated interference from the aircraft's electrical system, and vice versa.Other terminals 114 and 116 (e.g., 28V RETURN and CASE ground) may also exist in the system. - From
terminal 112, aircraft power is conducted tomotor controller 130 through diode D1. The presence or absence of aircraft power atterminal 112 is sensed bymotor controller 130 via the RET/EXT (RETRACT/EXTEND) input to the motor controller. If the signal on lead RET/EXT is “high” (e.g., 18 to 29 VDC),motor controller 130 drives motor 20 to retract the actuator to its retracted position (in which the actuator locks a door-opening mechanism of the aircraft).Motor 20 will stall the actuator in the retracted position as long as aircraft power continues to be supplied. - As means for electrical energy storage, capacitor C may be provided in
electrical energy accumulator 140. When aircraft DC power is present atterminal 112, capacitor C charges through resistor Rc and diode D2. Zener diode Z sets the capacitor charge voltage upper limit at a value appropriate to proper circuit operation. When capacitor C has charged to the Zener diode breakdown value, all further charging current, limited by charging resistor Rc, bypasses capacitor C and flows to RETURN through Zener diode Z. Other suitable means for electrical energy storage may also be used within the scope of the present invention. For example, a rechargeable battery may be alternately provided inelectrical energy accumulator 140 and charged using aircraft power fromterminal 112. - Sensing line RET/EXT signals the removal of aircraft power by going “low” (e.g., ˜0V), which signals
motor controller 130 to cause any subsequently applied electrical power to rotatemotor 20 in the direction required to extend the actuator to its unlocked position. After removal of aircraft DC power, power formotor 20 and formotor controller 130 during the extension stroke is provided by capacitor C through diode D3. The capacitor voltage will decay as current is drawn fromelectrical energy accumulator 140. However, the flight lock actuator electrical components are preferably sized so that the capacitor does not discharge below amotor controller 130 operational voltage value before the extension stroke of the actuator has been completed.Voltage regulator 150 supplies a constant control voltage for powering the control circuitry of motor controller 130 (as distinct from powering motor 20). - During either the retraction or extension stroke,
motor controller 130 preferably limits stroke velocity by limiting current throughmotor 20. For example, such current controller limiting may be achieved by pulse-width-modulation of the motor power signal, or by reducing the voltage available tomotor 20. Current throughmotor 20 is measured by a voltage drop across resistor R1. In order to limit impact velocity at the mechanical stops, the rotational speed ofmotor 20 is preferably limited, while still meeting a maximum allowable stroke time with appropriate margin.Motor 20 is typically equipped withHall effect sensors 31 that signal the rotor's angular position tomotor controller 130. Rotational speed ofmotor 20 may be ascertained using the frequency of the Hall effect sensors' signal. Alternately, because a permanent magnet motor generates a back-EMF proportional to its rotational speed, the generated back-EMF may be used bymotor controller 130 to ascertain the rotational speed ofmotor 20. - If
motor controller 130 senses a motor rotational speed in excess of a desired maximum speed, it may reduce the voltage available tomotor 20, or may pulse-width-modulate the motor power signal, so as to drop the motor rotational speed to the desired range. Ifcurrent limit circuitry 160 senses that the current passing throughmotor 20 is higher than a predetermined value that indicatesmotor 20 is in a state of powered stall,current limit circuitry 160 may signalmotor controller 130 to reduce the voltage available tomotor 20, or appropriately pulse-width-modulate the motor power signal, so that the current supplied during a period of powered stall does not overheatmotor 20. - The flight lock actuator's extension stroke is typically subject to a substantial aiding force from
spring 24 internal to the actuator and possibly also from springs external to the actuator in the aircraft door lock mechanism. In order to limit excessive extension stroke velocity caused by this aiding force, the flight lock actuator electrical system, in addition to limiting motor rotational speed by limiting the current tomotor 20, may seek to effectively brakemotor 20 usingdamper circuit 170. During the actuator's extension stroke, if current tomotor 20 has been reduced to substantially zero, while motor rotational speed remains above a desired maximum speed, the flight actuator electrical system may shunt back-EMF (electro-motive force) generated by the motor intodamper circuit 170 to place an electrical load onmotor 20. By temporarily transformingmotor 20 into such a loaded electrical generator, a braking effect is achieved onmotor 20.Logic circuitry 180, having inputs fromcurrent limit circuit 160 andmotor controller 130, monitors the predetermined condition for shunting current generated bymotor 20 todamper circuit 170. - To elaborate the last points, a permanent magnet motor generates a back-EMF proportional to its rotational speed. This generated back-EMF, or the signal frequency of
Hall effect sensors 31, may also be used bymotor controller 130 to ascertain the motor rotational speed.Logic circuitry 180 may monitor motor current information fromcurrent limit circuit 160 and motor rotational speed information frommotor controller 130. During the extension stroke, a motor current that is substantially zero, in combination with motor rotational speed in excess of a desired maximum speed, are signals indicating that the aiding force has drivenmotor 20 to an excessive speed despitemotor controller 130 reducing the motor voltage or pulse width to near zero. - When
logic circuitry 180 senses this condition, it reacts by throwing themotor controller 130 bridge into a full wave rectifier mode (i.e., all MOSFETs “off”) to shunt all current generated bymotor 20 through the MOSFETs' internal bypass diodes to a load resistor indamper circuit 170. By operatingmotor 20 as a generator in conjunction with the load resistor indamper circuit 170, the motor speed is reduced to a desired speed that ensures a controlled arrival into the mechanical stop. - The aircraft door flight lock actuator of the present invention utilizes a redundant energy storage system having mechanical and electrical energy storage means to store energy during the actuator's powered retraction stroke to the locked position, and subsequent period of powered stall in the locked position. Once aircraft power is removed from the flight lock actuator, the stored energy is used to power an extension stroke to the unlocked position. A brushless motor is used to power the actuator, and the actuator electrical system ensures that the motor does not overheat by limiting the current supplied to the motor to a desired maximum. The actuator electrical system ensures the controlled arrival of the actuator into its mechanical stops by limiting motor rotational speed using a current limiting method and a damper feature that effectively brakes the actuator motor. Utilizing these systems and methods, a flight lock actuator with substantially improved reliability is provided.
- It will be understood that the foregoing is only illustrative of the principles of the invention, and that various modifications can be made by those skilled in the art without departing from the scope and spirit of the invention. For example, although the foregoing describes an illustrative aircraft door flight lock actuator that retracts to lock and extends to release, it should be obvious to those skilled in the art that the present invention is equally adaptable to an actuator that extends to lock and retracts to release.
Claims (1)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/335,949 US7303167B2 (en) | 2001-11-13 | 2006-01-20 | Flight lock actuator with dual energy sources |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US34888101P | 2001-11-13 | 2001-11-13 | |
US10/260,470 US20030089826A1 (en) | 2001-11-13 | 2002-09-26 | Flight lock actuator with dual energy sources |
US10/658,930 US7137595B2 (en) | 2001-11-13 | 2003-09-09 | Flight lock actuator with dual energy sources |
US11/335,949 US7303167B2 (en) | 2001-11-13 | 2006-01-20 | Flight lock actuator with dual energy sources |
Related Parent Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/260,470 Division US20030089826A1 (en) | 2001-11-13 | 2002-09-26 | Flight lock actuator with dual energy sources |
US10/658,930 Division US7137595B2 (en) | 2001-11-13 | 2003-09-09 | Flight lock actuator with dual energy sources |
Publications (2)
Publication Number | Publication Date |
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US20060138281A1 true US20060138281A1 (en) | 2006-06-29 |
US7303167B2 US7303167B2 (en) | 2007-12-04 |
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Family Applications (3)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/260,470 Abandoned US20030089826A1 (en) | 2001-11-13 | 2002-09-26 | Flight lock actuator with dual energy sources |
US10/658,930 Expired - Lifetime US7137595B2 (en) | 2001-11-13 | 2003-09-09 | Flight lock actuator with dual energy sources |
US11/335,949 Expired - Lifetime US7303167B2 (en) | 2001-11-13 | 2006-01-20 | Flight lock actuator with dual energy sources |
Family Applications Before (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/260,470 Abandoned US20030089826A1 (en) | 2001-11-13 | 2002-09-26 | Flight lock actuator with dual energy sources |
US10/658,930 Expired - Lifetime US7137595B2 (en) | 2001-11-13 | 2003-09-09 | Flight lock actuator with dual energy sources |
Country Status (4)
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US (3) | US20030089826A1 (en) |
EP (1) | EP1310424B1 (en) |
AT (1) | ATE270999T1 (en) |
DE (1) | DE60200753T2 (en) |
Cited By (5)
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US20070193381A1 (en) * | 2002-09-11 | 2007-08-23 | Fernand Rodrigues | Screw actuator having means for blocking it in the event that it goes over to the secondary nut |
CN103161905A (en) * | 2011-12-14 | 2013-06-19 | 通用电气航空系统有限责任公司 | Automatically locking linear actuator |
US20140152201A1 (en) * | 2011-07-26 | 2014-06-05 | Moog Inc. | Electric motor clamping system |
US20150097455A1 (en) * | 2013-10-08 | 2015-04-09 | Nabtesco Corporation | Electromechanical actuator |
US11572935B2 (en) | 2019-07-03 | 2023-02-07 | Hydac International Gmbh | Linear drive system |
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US6837461B1 (en) * | 2003-08-08 | 2005-01-04 | Honeywell International Inc. | Balance load actuator |
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US7723935B2 (en) * | 2006-08-25 | 2010-05-25 | The Boeing Company | System and method for compartment control |
US8155804B2 (en) * | 2007-10-12 | 2012-04-10 | Airbus Operations Gmbh | Device and method for providing a flight status signal |
US8390160B2 (en) | 2010-01-14 | 2013-03-05 | Hamilton Sundstrand Corporation | Compact electromechanical actuator |
KR20150112940A (en) * | 2013-01-25 | 2015-10-07 | 가부시기가이샤 아이 에이 아이 | Actuator |
FR3015543B1 (en) * | 2013-12-24 | 2016-02-05 | Ratier Figeac Soc | DEVICE FOR OPENING AND CLOSING CONTROL OF AN AIRCRAFT DOOR |
US9435142B2 (en) | 2014-02-28 | 2016-09-06 | Schlage Lock Company Llc | Method of operating an access control system |
FR3040721A1 (en) | 2015-09-07 | 2017-03-10 | Latecoere | METHOD AND SYSTEM FOR EMERGENCY OPENING OF A VEHICLE CLOSURE ELEMENT, IN PARTICULAR AN AIRCRAFT CABIN DOOR |
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CN107314090A (en) * | 2017-07-04 | 2017-11-03 | 浙江捷昌线性驱动科技股份有限公司 | It is a kind of can bidirectional self-locking electric pushrod |
US11454048B2 (en) | 2018-11-07 | 2022-09-27 | The Boeing Company | Shape memory alloy locking apparatuses |
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US20230287707A1 (en) * | 2022-03-09 | 2023-09-14 | QuB LLC | Lock assembly |
Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4563908A (en) * | 1984-03-14 | 1986-01-14 | Plessey Incorporated | High speed, dual operated electromechanical actuator |
US4681286A (en) * | 1982-09-30 | 1987-07-21 | The Boeing Company | Door anti-hijacking latch/lock mechanism with pneumatic decompression override |
US5180038A (en) * | 1992-01-24 | 1993-01-19 | Orscheln Co. | Electronically controlled parking brake system |
US5194795A (en) * | 1989-05-29 | 1993-03-16 | Sekogiken | Drive system and a control unit therefor |
US5361024A (en) * | 1990-10-22 | 1994-11-01 | Syncro Corp. | Remote, electrical steering system with fault protection |
US5913763A (en) * | 1993-07-19 | 1999-06-22 | Dorma Door Controls, Inc. | Method for controlling the operational modes of a door in conjunction with a mechanical door control mechanism |
US6622963B1 (en) * | 2002-04-16 | 2003-09-23 | Honeywell International Inc. | System and method for controlling the movement of an aircraft engine cowl door |
US6902137B2 (en) * | 2002-09-09 | 2005-06-07 | Adams Rite Aerospace, Inc. | Aircraft door latch/lock mechanism with pneumatic decompression override |
US6951052B2 (en) * | 2001-05-05 | 2005-10-04 | Henrob Limited | Fastener insertion apparatus and method |
Family Cites Families (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2562689A (en) * | 1948-06-21 | 1951-07-31 | Earl Hovey C | Screw and nut transmission |
US5251851A (en) * | 1990-07-11 | 1993-10-12 | Deutsche Aerospace Airbus Gmbh | Door operating mechanism for opening and closing an aircraft door in response to a stored program |
US5367237A (en) * | 1992-06-15 | 1994-11-22 | Honeywell Inc. | Electromechanical actuator controller |
US5382890A (en) * | 1993-02-17 | 1995-01-17 | Pitney Bowes Inc. | Integrated circuit driver having current limiter for brushless motor |
US5744921A (en) * | 1996-05-02 | 1998-04-28 | Siemens Electric Limited | Control circuit for five-phase brushless DC motor |
US6109563A (en) * | 1996-09-30 | 2000-08-29 | Mcdonnell Douglas Corporation | Plug door operating mechanism |
DE19738131C1 (en) * | 1997-09-01 | 1998-10-01 | Pierre Meyers | Bolt operating system with lock bolt, electric adjusting unit and return system e.g. for door frame or panel |
JP3471596B2 (en) | 1998-02-16 | 2003-12-02 | アスモ株式会社 | Actuator |
JP4037539B2 (en) * | 1998-09-08 | 2008-01-23 | 株式会社ニフコ | Latch unit |
FR2784349B1 (en) * | 1998-10-09 | 2000-12-29 | Labinal | ACTUATOR FOR OPERATING AN ACCESS HATCH AND ACCESS HATCH COMPRISING SAME |
-
2002
- 2002-09-26 US US10/260,470 patent/US20030089826A1/en not_active Abandoned
- 2002-11-11 EP EP02257785A patent/EP1310424B1/en not_active Expired - Lifetime
- 2002-11-11 AT AT02257785T patent/ATE270999T1/en not_active IP Right Cessation
- 2002-11-11 DE DE60200753T patent/DE60200753T2/en not_active Expired - Fee Related
-
2003
- 2003-09-09 US US10/658,930 patent/US7137595B2/en not_active Expired - Lifetime
-
2006
- 2006-01-20 US US11/335,949 patent/US7303167B2/en not_active Expired - Lifetime
Patent Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4681286A (en) * | 1982-09-30 | 1987-07-21 | The Boeing Company | Door anti-hijacking latch/lock mechanism with pneumatic decompression override |
US4563908A (en) * | 1984-03-14 | 1986-01-14 | Plessey Incorporated | High speed, dual operated electromechanical actuator |
US5194795A (en) * | 1989-05-29 | 1993-03-16 | Sekogiken | Drive system and a control unit therefor |
US5361024A (en) * | 1990-10-22 | 1994-11-01 | Syncro Corp. | Remote, electrical steering system with fault protection |
US5180038A (en) * | 1992-01-24 | 1993-01-19 | Orscheln Co. | Electronically controlled parking brake system |
US5913763A (en) * | 1993-07-19 | 1999-06-22 | Dorma Door Controls, Inc. | Method for controlling the operational modes of a door in conjunction with a mechanical door control mechanism |
US6951052B2 (en) * | 2001-05-05 | 2005-10-04 | Henrob Limited | Fastener insertion apparatus and method |
US6622963B1 (en) * | 2002-04-16 | 2003-09-23 | Honeywell International Inc. | System and method for controlling the movement of an aircraft engine cowl door |
US6902137B2 (en) * | 2002-09-09 | 2005-06-07 | Adams Rite Aerospace, Inc. | Aircraft door latch/lock mechanism with pneumatic decompression override |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20070193381A1 (en) * | 2002-09-11 | 2007-08-23 | Fernand Rodrigues | Screw actuator having means for blocking it in the event that it goes over to the secondary nut |
US20140152201A1 (en) * | 2011-07-26 | 2014-06-05 | Moog Inc. | Electric motor clamping system |
US9614465B2 (en) * | 2011-07-26 | 2017-04-04 | Moog Inc. | Electric motor clamping system |
CN103161905A (en) * | 2011-12-14 | 2013-06-19 | 通用电气航空系统有限责任公司 | Automatically locking linear actuator |
US20150097455A1 (en) * | 2013-10-08 | 2015-04-09 | Nabtesco Corporation | Electromechanical actuator |
US9685838B2 (en) * | 2013-10-08 | 2017-06-20 | Nabtesco Corporation | Electromechanical actuator |
US11572935B2 (en) | 2019-07-03 | 2023-02-07 | Hydac International Gmbh | Linear drive system |
Also Published As
Publication number | Publication date |
---|---|
US20040056153A1 (en) | 2004-03-25 |
DE60200753T2 (en) | 2005-09-22 |
US20030089826A1 (en) | 2003-05-15 |
DE60200753D1 (en) | 2004-08-19 |
US7303167B2 (en) | 2007-12-04 |
ATE270999T1 (en) | 2004-07-15 |
EP1310424B1 (en) | 2004-07-14 |
EP1310424A1 (en) | 2003-05-14 |
US7137595B2 (en) | 2006-11-21 |
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